Adding buttons, the Zm, and IE

I am working on a zimlet that adds some buttons on the fly, basically stealing from the salesforce zimlet (thanks Marc). The following works fine in FF, but not IE. Furthermore, it only seems to fail when the page is refreshed.

Slightly different issue, same zimlet

Well, the business logic has changed on this, so that I am creating the buttons later. Somehow the timing made the issue go away.

But, I still need some help getting toolbar buttons added by a zimlet. We are approaching a release, so I really need to get this resolved. The current issue is that I can't get buttons added to the By Message View to do anything, it's like the listeners I define get wiped out before I can click.

Note that this code is executed after the page has been rendered. Also note that I am able to add buttons that work to the ZmConvListController using nearly identical code.

After lots of time in Firebug, I narrowed it down to DwtButton.prototype._mouseUpListener, specifically the evaluation of

Code:

if(this.isListenerRegistered(DwtEvent.SELECTION))

This is the difference between buttons that work and those that don't. This test evaluates to false with my new button. When I do:this._mailToolbar._buttons[this._quickOpDesc.id].isListenerRegistered(DwtEvent.SELECTION) from in the debugger console, right after the code above, it evaluates to true.
So I have to conclude that something is changing the state when switching to the By Message view. I don't know if this is a bug, or if there is something else I need to do. Help would be much appreciated.